Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F31/00—Inking arrangements or devices
  • B41F31/02—Ducts, containers, supply or metering devices
  • B41F31/04—Ducts, containers, supply or metering devices with duct-blades or like metering devices
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F31/00—Inking arrangements or devices
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F31/00—Inking arrangements or devices
  • B41F31/30—Arrangements for tripping, lifting, adjusting, or removing inking rollers; Supports, bearings, or forks therefor

Definitions

• the invention relates to the inking of printing machines with fatty ink.
• the main problem posed by the inking of an offset or typography press consists in regularly depositing, starting from a substantial mass of fatty ink, a layer of a few microns thick uniformly distributed over the printing parts of a printing cylinder. The ink deposited on this cylinder is then transferred to the paper, either directly in the case of typography, or indirectly, via a cylinder covered with a rubberized sheet called bianchet in the case of offset. .
• the quantity of ink released at the right of each screw must correspond to the ink consumption taken by each transverse zone of the paper. For example, if the print has several strips printed in the longitudinal direction and separated transversely by spaces which must remain blank, the adjustment screws of the inkwell must be tightened to the right of the white areas and more or less open to the right of the areas printed, according to the color intensity of these bands.
• fig. 1a schematically represents a short inking according to the method of French patent 1,341,700
• fig. 1b usually shows the developed diagram of the touch cylinder showing the succession of operations carried out at its periphery
• fig. 2 and 3 represent developed diagrams corresponding respectively to variants described in the above patent and in its first certificate of addition
• fig. 4a schematically shows another short inking device described in French patent 73 39 429
• fig. 4b represents the developed diagram of the touching cylinder corresponding to FIG. 4a
• fig. 5 shows a particular case of this device
• fig. 6 shows by comparison the general diagram of the method according to the invention
• fig. 7 shows the developed diagram of the touch cylinder
• fig. 8 shows a variant with an equalizing cylinder
• fig. 9 is an enlarged detail of the knife
• figs. 10 and 11 show a particular embodiment of the device, respectively in section along XX of FIG. 11, and according to XI-XI of FIG. 10.
• the wiper cylinder E is kept under pressure on the toucher T coated with a flexible material. These two cylinders rotate in the same direction of rotation so that the. ink film included in the contact zone in is entrained in one direction by the cylinder E and in the other direction by the feeler T. This film is therefore somehow sheared in its thickness. This results in an ink thickness e on the touchpad T independent of the quantities of unused ink upstream of the area m. The excess ink sheared at point m is evacuated by cylinder E and taken up by cylinder L which brings it back to the reserve q contained in the inkwell.
• fig. 3 shows the variant corresponding to the first certificate of addition of the aforementioned patent.
• the rolling cylinder L has been removed and the wiping cylinder E remains, but to avoid the return of the ink coming from the reserve on the sheared layer, two doctor blades R1 and R2 are placed which clean the surface of the wiping cylinder E before it comes into contact with the layer spread on the toucher T.
• the wiper cylinder E has been reduced in diameter to increase the pressure on the ink film and reduce its thickness.
• This cylinder has thus become a rod, still referenced E, which is kept in pressure over its entire length against the toucher T by a V-groove formed in a cross-member Tr.
• the doctor blades R1 and R2 of the previous device are replaced by the tangents x and y at the contact points of the rod E and its support Tr as shown in the diagram developed in FIG. 4b.
• These contact lines are supposed to prevent the ink from passing and coming to be superimposed on the sheared layer of thickness e.
• the thickness of the ink layer & is a few microns, a variation of 10% of this thickness results in a variation visible to the eye in the optical density of the printed product. It can therefore be seen that the lines x and y must be perfectly sealed or allow only a tiny film of ink of constant thickness to pass, a film which is superimposed on the film e of the sheared ink. In fact, when the system is new, it is practically impossible to obtain a perfect regularity of this parasitic film to the nearest micron. More or less dark streaks appear on the print.
• the rod speed should be readjusted permanently to keep the thickness constant due to variations in ink temperature at the rolling point.
• the rod E does not rotate any more and can be replaced by a cylindrical surface of radius r maintained in pressure on the touchter T.
• the thickness of sheared ink e then only depends on two factors, namely the radius r and penetration, apart from the usual factors such as ink viscosity, hardness of the flexible coating and speed V. When the speed increases, the penetration must therefore be increased. The limit is determined by the degradation of the touchpad surface.
• the invention like the state of the art, uses a touch cylinder with a flexible surface coated with a thin film of ink and depositing it on the printing form, this thin layer being determined in contact between this touch and a rigid cylinder at different peripheral speed.
• the ink is supplied at the point of contact while being carried by the surface of the touching cylinder, and partly withdrawn by the rigid cylinder, called for this reason wiping cylinder, in the invention on the contrary, the ink is supplied in the form of a calibrated film carried by the surface of the rigid cylinder, called for this reason the feed cylinder, and is spread at the point of contact with the touch cylinder.
• the reserve q of fatty ink is not in contact with the touching cylinder T but on the contrary with a feeding cylinder A, as it appears in particular in FIGS. 6, 7, 8 and 10.
• This mass q is between this feed cylinder A, a knife 1 and two cheeks 2 provided with indentations in an arc of a circle for bearing by interlocking transversely on the cylindrical surface of the feed cylinder A , which is naturally a rigid cylinder, preferably metallic.
• the knife 1 is secured to the cheeks 2 by means of micrometric screws 3 making it possible to adjust the distance d, visible in particular in FIG.
• the knife 1 is made integral, transversely with respect to the axis of the feed cylinder A, and by means of the screws 3 and of a cross-member 4, of the two cheeks 2 which bear on the cylinder A. In this way the distance d is independent of the inevitable run-out of this cylinder.
• the knife 1 is sharpened in the manner of a cutting tool, as shown in FIG. 9, with however a small rectified dish of width a close to a tenth of a millimeter so that the edge thus obtained is perfectly straight.
• the knife 1 cuts a slice of ink of thickness d, independent of the speed of the cylinder or of the characteristics of the ink.
• the knife edge never being in contact with the cylinder, no wear can result.
• the thickness d can vary from 10 to 60 microns depending on the precision of the micrometric screws.
• the cylinder A is movable and kept under pressure on the touch switch T, coated in the usual manner with a layer 5 of flexible material.
• the differential speed of the surfaces in contact at point 7 is obtained in this example by a rotation in the same direction of these two cylinders as shown by the arrows in FIG. 6.
• a doctor blade 6 eliminates from the periphery of the toucher T the ink not used by the printer form F and deposits it on the feeder cylinder A which brings it back into the reserve q.
• the application of the above formula then gives for d - ⁇ the value of 25 microns.
• a variation of 10% of the thickness ⁇ , ie 0.05 micron gives a variation representing 0.2% of the thickness of the layer d, resulting in a corresponding relative variation of the thickness e, c ' that is to say an absolute variation of 0.01 micron, negligible quantity and not perceptible on printing.
• this licking can cause small clumps of ink at the periphery of the toucher, which can be reduced in a known manner by placing a cylinder 8 rolling at the periphery of the touching cylinder. -.
• this cylinder 8 may prove to be insufficient to eliminate these clumps and obtain a perfectly uniform layer.
• an equalizing cylinder 9 which is driven in the direction reverse of the touching cylinder at a peripheral speed V 'close to the peripheral speed V of the touchor, either positively by gears, or by simple contact with the touchor.
• this cylinder 9 is in contact with the feeder A. Its action does not in any way modify the balance of ink thicknesses defined by the above formula. As seen in fig.
• the ink layer of thickness d arriving at the contact zone 10 between the equalizing cylinder 9 and the feed cylinder A is divided in two, one of which follows the curved path on the equalizing cylinder 9 to reach the contact zone 11 between the equalizing cylinder 9 and the toucher T, and the other follows the curved path, on the cylinder A, going from zone 10 to zone 7, then another curved path on the touching cylinder T going from the zone 7 to zone 11. Due to the speed differences between V * and v there is shearing of the ink layer d in zone 10, then rolling in zone 11. Thus, the entire thickness ea undergone an extremely efficient lamination in 10, 7 and 11, thus avoiding any ink agglomeration at the periphery of the touchter.
• this equalizing cylinder 9 can in a known manner be animated with an axial reciprocating movement to improve the regularity of the ink film and avoid the formation of possible streaks.
• the equalizing cylinder 9 no longer rotates at the speed V close to V but at a speed close to v.
• the spreading phenomenon which previously occurred in zone 7 (or 10) would occur in zone 11, and therefore it would no longer be necessary to have contact between the cylinders A and T in the zone 7.
• the ink layer of calibrated thickness d fed at low speed by the feed cylinder A can be spread over the touch cylinder T with a larger peripheral speed, either directly in the case examined first. , or indirectly in the case of the variant that we have just seen, without this going beyond the ambit of the invention.
• the method according to the invention it can be seen that one is thus in control of the value of the thickness e which becomes independent of the speed of the machine, insofar as the ratio v / V remains constant, and independent of the viscosity of the ink and its temperature, contrary to the state of the art.
• the apparatus is also insensitive to wear, due on the one hand to the absence of contact between the knife 1 and the feed cylinder A, and on the other hand to the low speed of rotation of the cylinder A relative to with the T-touch.
• a relatively simple material makes it possible to obtain both high inking precision and high working speed compatible with industrial exploitation.
• the two cheeks 2 are independent and provided on their faces opposite a .rainure 12 which does not open outwardly and in which comes to be supported each of the ends of the crosspiece 4 carrying the two screws 3 for micrometric adjustment of the knife 1, preferably with differential pitch.
• This knife 1 is itself guided in parallel in these grooves 12 and mounted by means of balls 13 to allow a slight angular adaptation of each of the cheeks 2 relative to the knife 1.
• Each of the cheeks 2 is supported on the cylinder A by a thicker part in which is cut the cylindrical notch exposed above, and this thick part ends in an oblique shoulder 14 on which comes into contact a pusher 15 actuated by a spring 16 and sliding itself obliquely in a flange 17 carrying the bearing 18 for journalling the cylinder A, a similar arrangement being provided at the other end of the cylinder.
• the oblique thrust produced by the pushers 15 on the cheeks produces both their tight application on the periphery of the cylinder A, and their mutual approach until contact with the balls 13, the seal between the ends of the knife 1 and the cheeks being ensured by the fitting in the grooves 12 and by the functional force of application in the drive direction.
• the two flanges 17 are integral with a cradle 19 oscillating around an axis 19a fixed in the frame 20.
• the penetration of the cylinder A into the touchor T is ensured by a pushing device 21, constituted by a spring or by preferably by a double-acting jack allowing the pressurization and depressurization, and limited in amplitude by a stop screw 22.
• the touching cylinder T, swiveling in the frame 20 in contact with the printing form F, is driven in the opposite direction and at the same tangential speed as the printing form F by means of gears 32 and 33.
• Apart from its shaft end 23 is preferably connected to a variable speed drive 24 allowing the v / V ratio to be adjusted at will, and from this latter comes a pulley 25 driving a larger pulley 27 by means of a belt 26 already providing a stage of reduction in the desired direction.
• This pulley 27 drives a shaft 28 swiveling in a fixed bearing 29, which shaft is connected to the shaft end 30 of the feed cylinder A by means of an oldham constant velocity joint or the like tolerating the movements of the cradle 19.
• doctor blade 6 and the equalizing cylinders 8 and 9 mounted on eccentrics to allow pressure adjustment.
• the invention could also be used to apply any thin film of a viscous liquid, such as paint, glue, or the like, to any surface which is scrolled by rotation or translation.

Landscapes

• Inking, Control Or Cleaning Of Printing Machines (AREA)
• Impression-Transfer Materials And Handling Thereof (AREA)
• Dot-Matrix Printers And Others (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=9273875

Family Applications (1)

Country Status (7)

Cited By (3)

Families Citing this family (14)

Citations (7)

Family Cites Families (10)

• 1982
  • 1982-05-10 FR FR8208107A patent/FR2526370B1/fr not_active Expired
• 1983
  • 1983-05-10 DE DE8383400946T patent/DE3375289D1/de not_active Expired
  • 1983-05-10 WO PCT/FR1983/000090 patent/WO1983004003A1/fr unknown
  • 1983-05-10 JP JP58501560A patent/JPS59500808A/ja active Pending
  • 1983-05-10 EP EP83400946A patent/EP0094320B1/fr not_active Expired
  • 1983-05-10 US US06/572,748 patent/US4542693A/en not_active Expired - Fee Related
  • 1983-05-10 AT AT83400946T patent/ATE31899T1/de not_active IP Right Cessation

Patent Citations (7)

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